You could do an integrity check of those files. Using a program like Tripwire or just an md5 calculator, you can get a fingerprint of the normal outlook.exe and iexplore.exe programs. Then, you can check to see if they have changed. If they have changed, it means you have either installed a patch or someone has altered them, possibly maliciously.
For more information on this topic, visit these other SearchSecurity.com resources:
Tech Tip: Inspect files and directories for unexpected changes
Tech Tip: Verify your data
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